reduce space on site server?

on our secondary site server there is a directory SMSPKG which contains copies of all of our packages (*.pkg). This machine is not our distribution point, which is a netapp device. How can I prohibit SMS to hold a copy on the server? This is more than 30 GB and I can't see the reason for this (maybe faster site by side communication while package update).

Can I take influence on this when I create a package? There is this menu that asks me for Source file: